www.rifondazionecomunista.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:57:26:15:7d:cc:0b:64:0f:43:5a:5b:8d:ca:b6:76:81:25 was issued on by Let's Encrypt.

This certificate has already expired and will cause a warning or error message in the browser it's still listed on this site to allow you to look back on previously issued certificates. If we have found any compliance issues with this certificate they will be shown below. I hope this certificate review is providing you the detailed information in a simple form you where looking for.


We have idenified some issues with this certificate:
  • Subscriber Certificate: commonName is deprecated. (BRs: 7.1.4.2.2)

Certificate Subject

CN=www.rifondazionecomunista.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:57:26:15:7d:cc:0b:64:0f:43:5a:5b:8d:ca:b6:76:81:25
Serial Number (int): 290992045970943513204872497333609503818021
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: 3c:ce:f9:47:5d:7a:fe:34:84:4d:2a:09:4b:e2:b8:71:03:0a:c4:90
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 21:b6:92:b5:08:36:6c:2e:98:06:d4:6c:a2:22:0b:77:54:d0:62:cd
Fingerprint (sha256): af:27:ca:d8:fa:d8:26:b4:64:f0:4e:e8:cb:6f:66:ff:9b:d1:a1:d4:01:da:06:55:8a:92:6a:c1:1a:a2:de:65

Issuing Certificate URL: http://cert.int-x3.letsencrypt.org/

Revocation information

OCSP Server: http://ocsp.int-x3.letsencrypt.org

Check the revocation status for certificate www.rifondazionecomunista.com

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for www.rifondazionecomunista.com

Public Key Algorithm

RSA

Key Size

4096

Signature Algorithm

SHA256 with RSA

Key Usage

Digital Signature
Key Encipherment

Extended Key Usages

Server Authentication
Client Authentication

Extensions

9 extensions
No unhandled critical extensions

CA Certificate

This is not a CA certificate

Subject Alternative Names

www.rifondazionecomunista.com

Other certificates including the domain name rifondazionecomunista.com

(limited to 100 certificates)

Certificate

The complete raw certificate details for www.rifondazionecomunista.com in PEM and ASN.1 format.

Certificate (PEM)

-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Public Key (PEM)

-----BEGIN PUBLIC KEY-----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-----END PUBLIC KEY-----

ASN.1 decoded

 [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . [c:2|t:0|true] OtherName 
 . . . . . . . . . . . . [c:0|t:2|false] INTEGER 2
 . . . . . . . . [c:0|t:2|false] INTEGER 290992045970943513204872497333609503818021
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.113549.1.1.11 (sha256WithRSAEncryption)
 . . . . . . . . . . . . [c:0|t:5|false] NULL 
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.6 (countryName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'US'
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.10 (organizationName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'Let's Encrypt'
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.3 (commonName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'Let's Encrypt Authority X3'
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-09-29 06:51:45 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-12-28 06:51:45 +0000 UTC
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.3 (commonName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'www.rifondazionecomunista.com'
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.113549.1.1.1 (rsaEncryption)
 . . . . . . . . . . . . . . . . [c:0|t:5|false] NULL 
 . . . . . . . . . . . . [c:0|t:3|false] BIT STRING (4208 bits)
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:2|false] INTEGER 753800874358550499336700132359605037615732601133240481861614473618768220344723405560406663471796787208221590718235158618672743516413075423264327887157632747956460736423550315376930670609473728334226060969485174528973435505387100789239063199222678869383586175337408741740712204288997503692028675553980862427555981090532886336183174292063915081158099537756143102332788273575765486921062109432678183840787764858844322773499008311505412732992051857320853306561508182530255074361184377968165057633489030854744964548519210546420149289312654961320838317827231691540854180138532138540958917587872187130772921246217994458460106426830508760779527333136172851821606675145772118213265746144714788007177151558712534225206117660162159128795661383448838639526698515139670361088081629476616778948801450124107313306838390269415833921610845404460112879796738537089334378074467912477827867476462013735791891677008129564527476807901294645710931462647004965484123183161919943313746510546802245969064709766978609454412044577098871146759172710219410183621213137255214063762393157030374630389726934412587899916607257458019661166308158537043745476913337496905123425124149107688557820948224758031833747890509859668921071698838485899607143861807612802860287973
 . . . . . . . . . . . . . . . . . . . . [c:0|t:2|false] INTEGER 65537

 . . . . . . . . [c:2|t:3|true] ORAddress 
 . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.15 (keyUsage)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:1|false] BOOLEAN true
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (4 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:3|false] BIT STRING (3 bits)
							05a0
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.37 (extKeyUsage)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (22 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.3.1 (serverAuth)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.3.2 (clientAuth)
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.19 (basicConstraints)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:1|false] BOOLEAN true
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (2 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.14 (subjectKeyIdentifier)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (22 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (20 bytes)
							3ccef9475d7afe34844d2a094be2b871030ac490
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.35 (authorityKeyIdentifier)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (24 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:0|false] OtherName a84a6a63047dddbae6d139b7a64565eff3a8eca1
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.1.1 (authorityInfoAccess)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (99 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.48.1 (ocsp)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:6|false] IA5String 'http://ocsp.int-x3.letsencrypt.org'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.48.2 (caIssuers)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:6|false] IA5String 'http://cert.int-x3.letsencrypt.org/'
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.17 (subjectAltName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (33 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.rifondazionecomunista.com'
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.32 (certificatePolicies)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (69 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.23.140.1.2.1 (Domain Validation Certificates Policy)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.4.1.44947.1.1.1
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.2.1 (cps)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:22|false] IA5String 'http://cps.letsencrypt.org'
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.4.1.11129.2.4.2
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (245 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (242 bytes)
							00f00076006f5376ac31f03119d89900a45115ff77151c11d902c10029068db2089a37d9130000016d7c0108f10000040300473045022100d0a6698fe9472586b06250f534cf2eef739f8cf09e38b8368867db891958875d022021c9405a34c5d9580446004078e3f463263792cd29f6281a39fe0bda9608a5ee00760063f2dbcde83bcc2ccf0b728427576b33a48d61778fbd75a638b1c768544bd88d0000016d7c010a0a0000040300473045022100efad210f935cc8a9215a732a91f83ea82832d0221b60acd176424ce9298d74490220578c8ca4b961b53182d0041bd6f2c8f25dd1fd77535188aa5da286b930c9cf6e
 . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.113549.1.1.11 (sha256WithRSAEncryption)
 . . . . . . . . [c:0|t:5|false] NULL 
 . . . . [c:0|t:3|false] BIT STRING (2048 bits)
		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